Answer to Question #35043 in C++ for khalid

Question

In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n.

The input in an integers n

The output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.

You should use the C++ i/o method,like cout and cin,<<,>> to finish it.